Air gun



AIR GUN Filed May 17, 1956 United States Patent AIR GUN Linus A. Gavin, Longmeadow, Mass., and Frederick H.

Jackman, Waterbury, Conn.

Application May 17, 1956, Serial No. 585,466

3 claims. (ci. 299-116) This invention relates to new andu'seful improvements in air guns such as used by mechanics and others for blowing chips, turnings and the like from machined work and from holes and cavities therein.

The principal objects of the invention-are directed to the provision of means in an air gun of the type disclosed in U. S. Letters Patent No. 2,320,964 of June 1, 1943 to facilitate the delivery of a jet of air at predetermined pressures within a range of pressures in combination with means for projecting a conical swirling stream of air forwardly around the air jet to prevent chips and turnings dislodged by the air jet from striking the operator.

Piping for compressed air is common in machine shops and the like and for one reason or another, in a certain department or location, thereof, it may be desired that the air from the jet not exceed a certain predetermined pressure. As an example, the prevailing -air pressure may be one hundred pounds per square inch while it may be desired that the usable air pressure not exceed seventy-tive pounds as a maximum.

To that end, according to one feature of the invention, internal means is provided in the air gun hereof which is adjustable to limit the opening movement of the air valve thereby to limit the air jet pressure to the predetermined maximum.

According to another feature of the invention, external manually adjustable means is provided to enable the operator of the gun to vary the jet pressure within arrange up to the predetermined seventy-tive pound maximum.

As a further feature of the invention, means is provided for providing a swirling conical air stream which is projected forwardly around the air jet as a safeguard to prevent chips, turnings and the like from striking the operator. The swirling conical air stream is an advantage as protection for the operator.

The novel features of the invention will be disclosed in the present preferred form thereof in connection with the 4accompanying drawings wherein;

The figure is a combined side elevational and longitudinal sectional View of an air gun embodying the novel features of the invention.

Referring now to the drawings more in detail the invention will be fully described.

A gun body is represented by 2 which has a grip end provided with an inlet 4 for connection to the flexible hose of a compressed air line. The outlet or discharge end of the body is represented by 6.

A well or cavity 8 is provided intermediate the opposite ends of the gun whichr has a valve seat 10 formed therein, as shown.

A valve 12 has a resilient seat 12 and a lower stem 14 reciprocable in the body. In its closed position, the valve seat 12 rests on the seat 10, as shown in the drawing.

A trigger 16 of usual form is pivoted at 18 to the body and the lower end of the stem 14 normally rests thereon.

As the trigger is operated, the valve 12 is elevated from off its seat to an open position above the seat.

The upper portion of the well is threaded and an internal valve stop 20, in screw threaded engagement therewith, may be screwed up or down for adjustment. A spring 22 between the stop 20 and valve 12 urges said valve onto its seat when the trigger 16 is released.

An external manually engageable stop 24 is adjustably screw threaded on the lower end of the stem 14 and its upper side is adapted to abut -a shelf 28 on the lower side of the body to limit upward movement of the stem and valve.

A closure cap 30 is in threaded engagement with the upper end of the well to close and seal the same, in the operation of the gun.

The outlet end of the gun is provided with a bore 32 and a main nozzle 34 has a body 36 disposed in said bore. The nozzle and body are provided with an air outlet passageway 38 in the lower end of which is screwed a jet 40 having an orifice, as shown, of a desired and predetermined area.

The body 36 of the main nozzle is provided with plural air grooves 42 thereabout and the inner periphery of the body outlet and main nozzle are formed with angularly related annular surfaces 44 and 46, which are spaced apart.

The body 36 of the main nozzle is secured in the bore 32 by pins 48 therethrough, as shown, to provide an annular outlet 50 for the desired width or thickness of conical air stream therefrom.

A passageway 52 provided in the body extends from the air inlet 4 to the well 8 above the valve 12 and a second passageway 54 extends from the well 8 below said valve 12 to the bore 32. Air entering the inlet of the gun will be discharged from the jet 40 and annular outlet 50 when the valve is elevated to upper open position by the trigger.

The surfaces 44 and 46 may be varied and related as desired to provide the angle of the cone of air discharged from the outlet 50. The part 36 is pinned in the body in such a Way as to provide the desired width of opening 50 and thereby the width of conical air stream.

The internal stop 20 may be adjusted to limit opening movement of the valve by the trigger and thereby limit the air pressure discharged by the jet 40 to a maximum. On release of the trigger the spring 24 urges the valve onto its seat to cut ol the flow of air.

The external stop 24 may be manually adjusted so as to limit upward opening of the stem and valve and thereby provide a desired pressure at the jet which may be relatively less than the maximum. Or the stop 24 may be adjusted so that the valve abuts the stop 20 to obtain the maximum pressure from the jet member 40.

Thus air pressure at the jet may be a predetermined maximum by adjustment of the internal stop or less than maximum by manual adjustment of the external stop. In other words the manual adjustment may be inoperative so that pressure is controlled by the internal stop or pressure may be under the control of the external stop, all as may be desired.

The grooves A42 of the nozzle body 36 may be of various widths and they may be disposed at any desired angle relative to the longitudinal axis of the body. There may be as many grooves as desired so that with said angular grooves the desired swirling of the conical air stream may result.

Various changes and modification may be made in the form of the device without departing from the spirit and scope of the invention and it is desired therefore to be limited, if at all, by the appended claims rather than by the foregoing disclosure.

What it is desired to claim and secure by Letters Patent of the United States is:

1. An air gun comprising in combination, a body having an air inlet and discharge jet means and a well provided with a valve seat, said body having air passageways from said inlet to said well above said seat and from said well below said seat to said jet means, a valve engageable with said seat in closed position thereof having a stem extending through said body, spring means urging said valve towards said seat, a trigger operable to act on and elevate said stem to move said valve from said seat, stop means adjustable in said Well engageable by said valve in upper position thereof, and a stop member independently adjustable on said stem externally of the body and adapted to abut said body as said stem is elevated by said trigger.

2. The combination in an air gun of, a body having an outlet end provided with a bore, a nozzle member having an inner elongated body fixed in said bore and an air jet in the outer end thereof, said nozzle body 20 provided with circumferentially spaced air grooves on the 4 outer side thereof disposed angularlyrelative to the longitudinal axis thereof for swirling air to an annular outlet, said body of the nozzle member and outlet end of the bore of the body being formed and related to provide an annular relatively narrow outlet for receiving air from said grooves and for discharging air.

3. An air gun set forth in claim 2 wherein said nozzle body and outlet end of the base of the body at said annular outlet are formed with relatively spaced and continuous angularly related faces for forming swirling air therefrom into a cone thereof around said air jet.

References Cited in the file of this patent UNITED STATES PATENTS 1,444,549 Merrill Feb. 6, 1923 1,821,206 Caswell Sept. l, 1931 2,320,964 Yates June 1, 1943 2,627,418 Ainsworth Feb. 3, 1953 FOREIGN PATENTS 16,784 Great Britain July 22, 1913 

